Micrometer-calipers



(No Model.)

J. M. IRMEN. MIOROME'IER GALIPERS.

No. 411,444. Patented Sept. 24, 1889.

Wfz'mewem Inventor.

N PETERS, Phnto-Litmgraphcn Washinginn. D. C.

UNITED STATES PATENT OFFICE.

JOHN M. IRMEN, OF ATLANTIC, IowA.

MlCROMETER-CALIPERS.

SPECIFICATION forming part of Letters Patent No. 411,444, datedSeptember 24, 1889.. Application filed April 23, 1889- Serial No.308,341. (No model.)

To a. whom it may concern.-

Be it known that 1, JOHN M. IRMEN, a citizen of the United States,residing at the city of Atlantic, in the county of Cass and State ofIowa, have invented certain new and useful Improvements in Calipers, ofwhich the following is a specification.

My invention relates to improvements in calipers in which one jaw isstationary and the other actuated by a threaded rod; and the objects ofmy improvements are to provide calipers that are accurate, durable, andadapted to measure the caliber of small things, and of any short smallthing that proj ects from a larger body. I attain these objects by thedevice illustrated in the accompanying drawings, in which- Figure 1 is aperspective View of the calipers. Fig. 2 is a detailed perspective viewof the stationary jaw and screw or threaded stem attached thereto. Fig.3 is a detailed perspective view of the movable jaw and threaded rodthat actuates it.

Similar letters refer to similar parts throughout the several views.

The frame of the calipers is of ordinary construction, and consists ofthe base D, the upright support (Z, and the upright support 6, havingthe slit m and screw a. The frame has secured to it a scale bar 13, andthe threaded rod 0 has secured to it the graduated wheel A, both thescale and wheel being such as are ordinarily used in the construction ofthis class of calipers. The threaded rod 0 passes through a threadedaperture adapted to receive it in the support eand has secured to oneend the thumb-piece F. The jaw G is firmly secured to the end of the rod0 and has a greater diameter than the rod. The stationary jaw E isprovided with a screw or threaded stem 2', which passes through athreaded aperture in the support (Z adapted to receive it, thus adjustably securing the jaw to the support (Z. The diameters of the jawsare the same, and they extend upward flush with or above the top of thesupport (Z.

The calipers are of ordinary construction, excepting the jaws E and G.In this class of.calipers as commonly made the jaws are formed bybeveling the adjacent ends of the screw i and threaded rod 0, so thatthe jaws are usually of smaller and never of larger diameter than thescrew and threaded rod, and the uppermost portions of the jaws arealways below the top of the support of the stationary jaw, thusrendering it impossible to take the caliber of the short gudgeons orjournals which are attached to watch-wheels and other wheels, becausethewheel comes in contact with the top of one or both of the supports, thuspreventing the gudgeon from being placed between the jaws. There aremany other things the size of which cannot be measured with this classof calipers on account of the jaws being below the tops of theirsupports.

My improvement consists in enlarging the adjacent ends of the SCIQWt andthreaded rod 0, and in placing the jaws in such a position that theirupper parts are flush with or project above the top of the stationary-jaw support cl.

By means of my improvement the size and caliber of many things can bemeasured, which cannot be with calipers as ordinarily constructed.

My improvement adapts this class of calipers to many new uses.

My improved calipers are operated, as this class of calipers usuallyare, by turning the threaded rod 0, thus moving the jaw G to and fromthe stationary jaw E.

I am aware of calipers having the graduated wheel, scale, adjustablestationary jaw, the threaded rod, and a frame such as I have shown anddescribed. Therefore I do not claim such calipers as my invention; but

What I do claim as my invention, and desire to secure by Letters Patent,is-

1 The frame, the threaded rod which passes through a threaded aperturein its support adapted to receive it, the circular jaw having alongitudinal and revolving motion, which is secured to the inner end ofthe threaded rod, the stationary-jaw stem or shank which enters anaperture in its support adapted to receive it, and the circularstationary jaw which is secured to the inner end of its stem or shankand which extends upward above its support, the movable circular jawbeing constructed of larger diameter than the spaces as Well as externaldiameters, all cornbined substantially as described and shown.

2. Calipers provided with a movable circular jaw having a longitudinaland revolving 10 motion and being of greater diameter than the rod towhich it is secured and by which it is actuated, substantially asdescribed.

JOHN M. IRMEN.

WVitnesses:

MAGGIE IRMEN, WILL LANDMESSER.

